Can closing machine



Oct. 31, 1961 2. P. RENZl 3,006,304

CAN CLOSING MACHINE Filed May 25, 1957 5 Sheets-Sheet 1 FIG FIG. 2 Ii G H j INVENTOR. r ZENO PETER RENZI ATTORNEYS 3 Sheets-Sheet 2 Filed May 23, 1957 FIG.5

S M a Y L z 0 O d, l M .T e Wm? El 0 7 o 4 T 2 7 A %J wfifi fi z E v j 42 7x a 1 1 3 43% Oct. 31, 1961 z. P. RENZI CAN CLOSING MACHINE 3 Sheets-Sheet 5 Filed May 23, 1957 FIG. 7

FIG. 8

INVENTOR.

Jm P/ United States Patent Can Company, New York, N.Y., a corporation of New Jersey FiledMay 23, 1957, Ser. No. 661,150 4 Claims. (Cl. 113-19) The present invention relates to machines for seaming end closures to container bodies by an interfolding or other bending of flanges .on the closures and the bodies and has particular reference to a novel pressure device for applying multiple axial pressures against the closure to prevent its slipping during the seaming operation.

In the manufacture of sheet metal cans orcontainers the open ends of the cans or canbodies are closed with covers or end closures which are permanently held in place by the well known double seam formed by the interfolding of flanges provided on the end closures and on the can bodies. Two methods are commonly used to effect this seaming operation, one in which the can is rotated and the other in which the seaming head is revolved about the can.

The interfolding of the flanges to produce the uniting end seam usually is effected in two stages, a firstoperation in which most of the interfolding is efiected and a second operation in which the final shaping and compression of the interfolded flanges is effected.

Considerable radial pressure is required to interfold the flanges to produce the end seam, especially during the second operation when the seam is rolled tight. This pressure condition is further aggravated when the container material varies in thickness and/or hardness. When such pressures are required to bend the container material, the container or its closure often slips or skids on the chuck in the seaming head, with the result that the seaming rollers momentarily stop or drag i.e. the rollers and the flanges being bent move together instead of relative to each other, during the travel of the rollers around the closure. This action produces faulty end seams through irregular formation of the seam. 'Such faulty seams are liable to leak and cause subsequent trouble.

Although conventional closing machines are constructed to hold the container and its closure tightlyunder axial pressure against the seaming head chuck during the seaming operation, it has been found that this axial pressure under certain conditions is insufiicient to hold the closure against rotation relative to the chuck and that additional axial pressure applied at the proper tirne, usually during the second operation, is required to hold'the closure in a fixed relation on the chuck to provide for the proper formation of the end seam.

It is therefore an object of the instant invention to provide for the application of :a variable pressure against the container and its closure axially, to hold the container and closure in place in the seaming head against skidding or rotative movement relative to the head chuck during the seaming operation to insure :proper tightness and formation of the end seam.

Another object is to provide fora predetermined axial pressure during one portion of theseam forming operation and for a different axial pressure during another portion of the operation to insure against slipping of the container and closure and improper formation of the seam.

Another object is to ,provide for the carefully controlled application of a sudden sharp increase in axial pressure against the container and its closure at the be ginning of the second operation without requiring excessive motion of the parts applying the pressure.

Another object is the provision of a variablepressure ice device which permits of a mechanically wide range of pressures.

Another object is the provision of a variable pressure ,device which is readily incorporated in the lifter mechanism of aconventional can closing machine.

Numerous other objects and advantages of the invention willbe apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referringto the drawings:

FIGURE 1 is a fragmentary sectional view of a seaming machine showing a lifter pad mechanism embodying the instant invention;

FIGS. 2, 3 and 4 are enlarged fragmentary sectional views showing different stages of interfolding the flanges of a container body and its closure to produce an end seam;

'FIG. 5 is a view similar to FIG. 1 showing certain of the parts in a difierent position;

FIG. 6 is 'a reduced scale elevational View of a development of acam used in the machine; and

.FIGS. 7 and 8 are enlarged exploded views which taken together illustrate the parts of the lifter pad and their relative position in the mechanism.

As a preferred and exemplary embodiment of the instant invention the drawings illustrate principal parts of a conventional can seaming or closing machine for permanently uniting a can end closure or cover A (FIGS. 1 and 2) to an end of a can body B to produce a container for filling or to finally close a container already filled with a product. Such a conventional can closing machine is disclosed in detail in United States Patent 1,601,910 issued October 5, 1926 to P. W. Fleischer et al. on Multispindle Double Seamer.

The closure A and the body B preferably are made of sheet metal such as tin plate, black iron or the like material and are formed with respective outwardly extending flanges C, D (FIG. 2) which are interfolded to produce a uniting double seam E as shown in FIG. 4. The interfolding of the flanges C, D preferably is effected by a conventional seaming head F (FIG. 1) having a stationary chuck 11 which fits against the can closure A and a plurality of seaming rollers 12 which rotate around the peripheral outer edge of the closure flange C and patent. One set of rollers, called the first operation roliers bends the flanges C, D into the position shown 'inFIG. '3 and the other set of rollers, called the second operation rollers finishes the bending action and produces the finished seam as shown in FIG. 4.

In the closing machine,'the can body B is received on a lifter pad-14 (FIG. 1) and a closure A is loosely applied to the top open end of the body, with the closure and body flanges C, D overlapping as shown in FIG. 2. Usually the can end or closure A is formed with a counter- "Theihfter pad .14 lifts the body B with its loosely applied closure A upwardly into the seaming head F as shown iniFIG. 5 where the chuck '11 fits into the countersunk portion of the closure with the outer edge of the "chuck engaging and backing-up the upright wall H of the closure. .T he lifter pad 14 firmly clamps the body and 3 rollers 12 move in to perform the first and second seaming operations. In performing this seaming operation the rollers 12 may stand still and the lifter 14 and its associated body B and closure A may be rotated or the rollers 12 may be revolved and the lifter and its body and closure held against rotation.

In the conventional multispindle can closing machine there are a plurality of lifter pads 14 (FIG. 1) carried in a horizontally disposed disc or turret 16 mounted on a vertical shaft 17 journaled in bearings formed in a frame 18 which constitutes the main frame of the machine. The shaft is driven in any suitable manner so as to rotate the disc or turret 16 through its cycle of operation. There usually is one seaming head F mounted above each lifter pad 14 and moveable with the turret 16 and these heads or the lifter pads are rotated from the vertical shaft 17 in time with the travel of the turret. During the rotation of the turret 16, each lifter pad is raised and lowered by a cam roller 21 which traverses a stationary cam track 22 constituting lifter timing devices (FIGS. 1, and 6) attached to the machine frame 18. Such a cam track also is clearly shown in FIGS. 3 and 33 of the above mentioned Fleischer patent.

During the first operation, when the first operation seaming rollers 12 are squeezing in against the outer periphery of the closure and body flanges C, D to interfold them as shown in FIGS. 3 and 4, a slight shortening of the can body takes place as a result of the reshaping of the body and cover flanges. In order to produce a properly tight seam, the lifter pad 14 is required to maintain a substantially constant predetermined pressure axially against the body and its closure during the first operation. It is therefore necessary to compensate for this shortening action to maintain the flanges in proper relation and to keep the closure tight against the chuck 11 to prevent turning or skidding of the closure relative to the chuck. This is usually effected by a gradual rise L to M in the cam track 22 (FIG. 6).

When the first operation seaming rollers 12 complete their cycle of operation and leave the interfolded flanges C, D in the condition shown in FIG. 3, they recede from the partially formed seam and the second operation rollers 12 move in against the partially formed seam to complete it as shown in FIG. 4. These second operation seaming rollers 12 are required to press harder against the flanges to complete the inter-folding, and thus they exert a greater drag on the closure A, with the result that an abrupt, sharp increase in the pressure exerted axially against the body and the closure is required to prevent skidding of the closure on the chuck and to thus produce a properly formed end seam E as shown in FIG. 4.

The controlled production of this sharp increase in the axial pressure exerted against the body and its closure during the seaming operation is an important feature of this invention and is efiected preferably through means operating against the lifter pad 14 as the pad is lifted by the cam track 22 in time with the rotation of the seaming head F. For this purpose the lifter pad 14 is formed With a depending shaft or stem 31 (FIGS. 1, 5 and 7) which is rotatably mounted on a pair of ball bearings 32 carried in a cylindrical vertically disposed housing 33 slideably disposed in a vertical sleeve 34. The sleeve 34 is slideable vertically in a bearing 35 secured to the rotatable disc 16. Below the bearing 35, the sleeve 34 carries the cam roller 21 and through this roller and its cam track 22 the sleeve is raised and lowered to lift the can body B and its closure A upwardly into the seaming head F as hereinbefore mentioned. The upper end of the sleeve 34 preferably carries a surrounding dust guard 36 to keep foreign matter out of the ball bearings 32.

Within the sleeve 34, there is provided a pair of compression coil springs 41, 42, arranged one above the other in axial alignment and separated by a washer 43. The upper spring 41 is a relatively heavy spring utilized for the second operation seaming cycle, and is interposed between the bottom of the housing 33 and the top of the washer 43. Lugs 45, 46 formed respectively on the bottom of the housing 33 and on the top of the washer 43 keep the spring 41 in axial alignment with the sleeve 34.

The lower spring 42 is a relatively light spring and is utilized for the first operation seaming cycle. This light spring 42 is interposed between the bottom of the washer 43 and a nut 48 which is threadedly and adjustably engaged in a. collar 49 loosely disposed in the lower end of the sleeve 34. An annular key 51 disposed in a recess 52 inside the sleeve 34 retains the collar 49 against displacement from the sleeve, while a pin 54 in the sleeve engages in a vertical groove 55 in the collar to hold the latter against rotation.

By rotating the nut 48 in the threaded collar 49 the pressure of the light spring 42 may be adjusted to exert the proper pressure on the can body B and its closure A during the first operation. For this purpose an interior face 57 of the nut 48 (see also FIG. 8) is provided with vertical splines 58 which mesh with and cooperate with similar splines 59 in an adjusting member 61 disposed in axial alignment with the nut 48 and rotatably carried in the collar 49. The lower end of the adjusting member 61 is provided with a hex head 62 for a conventional wrench. Through rotation of the adjusting member 61, the nut 48 can be rotated in the collar 49 while the splines 58, 59 permit of vertical movement of the nut 48 relative to the collar. The adjusting member 61 is normally locked against rotation by a pin 63 carried in the collar 49 and engaging in one of the splines 59 in the member. By lifting the member so as to raise the spline above the pin, the member is unlocked and can be rotated.

Through this arrangement the lower or light spring 42 urges the lifter pad 14 and the can body B with its superimposed closure A upwardly to press the closure tightly against the seaming head chuck 11 with a predetermined comparatively light pressure during the first operation seaming cycle. The heavy spring 41 is preferably so stiff that there is little, or at best, slight compression of it during this first operation cycle. Thus with the two springs acting independently a mechanically wider range of pressures may be obtained over the use of a single spring.

The gradual rise between the points L-M of the cam 22 preferably is slightly in excess of that necessary to compensate for the shortening of the can body height during the first operation, so that the light spring 42 is subjected to a gradual compression during this first operation with the result that the washer 43 is engaged by a solid stop 64, carried by the nut 48, toward the end of this first operation. Therefore, just prior to, or simultaneously with the beginning of the second operation, the cam roller 21 rides up a short comparatively gentle rise MN of the cam 22, thus compressing the heavy spring 41 and producing a sudden sharp increase in the axial pressure exerted against the body B and closure A, which pressure is maintained throughout the second operation, when the drag exerted by the seaming rolls is at a maximum, to insure against skidding or relative rotative movement between the closure and the chuck during the completion of the end seam.

Since the'spring 41 is heavy, the sharp increase in pressure can be obtained without requiring too severe a rise in the cam section MN. Thus, the angle of rise of the section N, while greater than that of the section LM, is still Within the practical working limits of smoothly operating high speed machinery. Since there is normally no appreciable shortening of the can body height during the second operation there is no need to provide a gradual rise in the cam track 22 following the rise MN in order to maintain a constant lifter pressure during this cycle.

The stop 64 preferably is formed as an adjustable screw threadedly engaged in the nut 48 and extending up adjacent the bottom of the spacing washer 43. At its lower end the stop screw 64 is provided with a flat tongue 66 which engages in a slot 67 of an adjusting pin 68 disposed vertically in the adjusting member 61 in axial alignment therewith and shouldered against a ledge 69 in the member 61 to prevent displacement therefrom. The pin 68 extends through the adjusting member 61 and below the member is provided with a hexagonal head 72 for a conventional wrench. A light spring 73 disposed between the bottom of the tongue 66 and the pin 68 holds the pin 68 against the ledge 69. By rotation of the pin 68, the stop screw 64 can be elevated or lowered to precisely locate the top of the screw for seating engagement against the spacing Washer 43 under a precise pressure on the light spring 42,.

Provision is made for locking the stop screw 64 in an adjusted position. For this purpose the adjusting member 61 carries a lock pin 75 (FIGS. 1 and 7) the inner end of which engages in one of a series of notches 76 formed in the outer face of the pin 68. By lifting the pin 68 so as to raise the engaged notch 76 above the lock pin 75, the pin 68 is unlocked and can be rotated to effect the adjustment of the stop screw 64.

It is thought that the invention and many of its at tendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit can body and its superimposed closure from a lowermost advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In a can closing machine comprising a chuck, seaming rollers movable radially toward and from said chuck and cooperating therewith in succession to eifect a cycle of first and second seaming operations in forming a double seam uniting flange parts of a can body and a superimposed closure, a lifter unit mounted for vertical reciprocation under said chuck and including a sleeve having a support mounted for axial reciprocation therein and connected through resilient means to said sleeve, said support being adapted for holding thereon a can body and a superimposed closure in alignment with said chuck, and means for vertically reciprocating said sleeve to raise said can body and its superimposed closure from a lowermost position to a first clamping position against said chuck and, later in the seam forming cycle, to raise said sleeve further and then, after completion of the seam forming cycle, to lower said body and closure to said lowermost position, the improvement wherein said sleeve is formed with a ledge on a lower inner portion thereof, and said resilient means comprises a relatively light lower spring resting on said ledge, a stop member on said sleeve adjacent the top of said lower spring, a Washer resting upon the upper end of said spring and normally spaced vertically from said stop member, an upper relatively heavy spring resting at its lower end on said washer and carrying said support on its upper end, whereby said means for vertically reciprocating said sleeve first raises said can body and closure thereon into contact with said chuck, then compresses said relatively light spring to apply light clamping pressure preliminary to and during a said first seaming operation on the flange portions of the can body U and closure, then abuts said stop against said washer, and thereafter compresses said relatively heavy spring to apply increased clamping pressure on said can parts during said second seaming operation and completion of the double seam between said can body and closure flanges to insure precise formation of said double seam.

2. In a seam forming machine for uniting can parts such as end closures and bodies comprising a seaming head including a chuck and seaming rollers adjacent to and cooperabie with said chuck for forming flange portions of said can parts into end seams while said flange portions are interposed between said rollers and chuck, a movable support for holding loosely assembled can parts thereon and in axial alignment with said chuck, actuating means for moving said support axially toward said chuck to clamp said can parts therebetween, resilient means under said support and interposed between said support and said actuating means so that the can parts are clamped between said support and chuck under yieldably applied pressure, and means for moving said seaming rollers successively toward said chuck to effect a cycle of seaming opera-tions for uniting said can parts in an end seam in timed relation with said actuating means, the improvement wherein said resilient means is a variable pressure means including a plurality of difiering strengths of resilient elements Within said sleeve, said elements being arranged one above the other, means interposed between said elements for shifting the load from a resilient element of lesser strength to one of greater strength as said sleeve rises for successive cooperation with said support to apply increasing resilient pressure to said support for clamping said can parts between said support and chuck as said seaming operations progress, witha quick increase in said pressure between operations as the load is thus shifted from one element to another, whereby the relative positions of said chuck and the can parts clamped thereagainst remain fixed and the precise formation of said end seam is insured.

3. A machine of the character defined in claim 2 wherein said means interposed between said resilient elements include a dividing washer between a pair of said elemen-ts, said elements being arranged in axial alignment with said support and chuck, and also a solid stop engageable by said washer to stop further compression of one of said resilient elements, whereby a predetermined compression of a said resilient element effects engagement between said stop and washer to suspend effectiveness of that element and leave the other of said pair of resilient elements thereafter effective to apply resilient pressure to the clamped can parts.

4. A machine of the character defined in claim 3 wherein said resilient elements are compression springs of different strengths.

References iiited in the file of this patent UNITED STATES PATENTS 711,204 Gay Oct. 14, 1902 1,450,418 Guenther Apr. 3, 1923 1,621,580 Cameron Mar. 22, 1927 1,752,328 Cameron Apr. 1, 1930 2,085,879 Trump July 6, 1937 2,184,493 Gladfelter Dec. 26, 1939 

